With the growth of e-mail and text messages (e.g., SMS messages) there is an on-going shift in mobile communications from synchronous communications to asynchronous communications. In this context, synchronous communications involve the calling and called party in direct communication during the exchange of information. Asynchronous communications occur when the calling party and called party are not in direct communication. Examples of popular asynchronous communication methods include Text Messaging, such as Short Messaging Service (SMS), multimedia messaging service (MMS), Electronic Mail (e-mail), Facsimile (fax), and numeric-only or alphanumeric paging (paging), voice mail, etc.
Asynchronous communication modes do not provide mechanisms to ensure that the intended recipient of a message will actually read, listen, display, act upon the message (i.e., open the message). At best, senders can request a read receipt, such as provided by most e-mail systems, or an acknowledgement that the message has been received. Additionally, current asynchronous communication modes do not rank the priority levels of sent messages. Using traditional e-mail as an example, flags may be set by senders to denote that the message is urgent. However, the recipient decides when to read the message. Consequently in urgent situations some messages may not be read in time or read at all. These problems may limit the use of current asynchronous communication modes for communicating information with deadlines or urgent priority.